A sound attenuation material includes a plurality of particles, each having a core and an elastic or compliant coating around the core, and a matrix surrounding the plurality of particles, the matrix being less dense than the core. A method of manufacturing sound attenuating materials includes adding an elastic or compliant coating to core particles and drying and/or curing the coating, mixing the coated core particles into a matrix material, and pouring the mixture into a mold. The core particles are denser than the matrix material.